Novel printing and coating system

ABSTRACT

A PROCESS FOR PRODUCING DECORATIVE COATINGS. A CONVERTIBLE LACQUER BASED ON CASTOR OIL IS APPLIED OVER AN ETHYL CELLULOSE INK OR LACQUER COATING ON A SUITABLE SUBSTRATE TO PRODUCE A TEXTURED OR &#34;ORANGE PEEL&#34; EFFECT. BOTH THE CONVERTIBLE CASTOR OIL BASED LACQUER AND THE ETHYL CELLULOSE INK OR LACQUER COATING MAY BE EITHER CLEAR OR COLORED, DEPENDING ON THE DESIRED EFFECT.

United States Patent Office 3,829,323 Patented Aug. 13, 1974 3,829,323 NOVEL PRINTING AND COATING SYSTEM John N. Kirch, Cincinnati,Ohio, assignor to Borden, Inc., Columbus, Ohio No Drawing. Filed Dec. 23, 1971, Ser. No. 211,638

Int. Cl. B44d 1/14 U.S. Cl. 117-45 11 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Heretofore, the attainment of a textured printed or lacquered surface was difiicult to achieve. In the case of a textured printed surface, it was necessary that either the substrate or the printing surface of the printing press be textured. Similarly, textured lacquered surfaces required the use, for example, of a textured substrate or a textured roller for application of the lacquer to the substrate. However, depending on the leveling tendency of the ink or lacquer, i.e., the tendency for surface irregularities to level out, the effect of textured printing surfaces or applicator rolls may be negated. Furthermore, by means of the foregoing prior art processes it is extremely ditficult, if not impossible, to achieve a contrast finish in which part of the surface is smooth and part is textured.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a process for producing textured printed and lacquered surfaces.

It is another object of this invention to provide a process for producing textured printed and lacquered surfaces on smooth substrates.

It is yet another object of this invention to provide a process for producing printed and lacquered surfaces that are partially smooth and partially textured.

Yet other objects and advantages of this invention will be apparent to those skilled in the art from the following description of this invention.

The foregoing objects are achieved according to the practice of this invention. Broadly, this invention consists of a process for producing textured printed and lacquered surfaces comprising:

a. applying a convertible castor oil based lacquer over an ethyl cellulose based coating on a suitable substrate; and

b. heating to cause said convertible castor oil based lacquer to dry.

When the convertible castor oil based lacquer is applied to the smooth ethyl cellulose based coating on the substrate, a textured or orange peel effect results. That is, the previously smooth ethyl cellulose based coating reacts with the convertible castor oil based lacquer to undergo a change whereby the resultant coating acquires a texture similar in appearance to that of an orange peel, hence the term orange peel in connection with the appearance of the resultant coating. The resultant coating is then heated to cause conversion, i.e., drying, of the convertible castor oil based lacquer.

The instant invention does not require the use of textured applicator rolls or printing surfaces and there is no tendency for the coating to undergo leveling. Furthermore, the process of the instant invention readily allows for the attainment of a contrast finish where part of the coated surface is smooth and part is textured.

DETAILED DESCRIPTION By the process of this invention there may be obtained textured printed or lacquered coatings having a texture similar in appearance to an orange peel. Not only may the entire printed or lacquered surface acquire a textured, orange peel effect but, if desired, there may be obtained a contrast finish wherein part of the printed or lacquered surface is textured and part is smooth. The textured coatings obtained by the practice of this invention are not only decorative, but they also have utility in slide-resistant packaging. The textured, orange peel effect is attained by applying a convertible castor oil based lacquer over an ethyl cellulose based coating on a suitable substrate and thereafter heating to cause the castor oil based lacquer to dry.

The convertible castor oil based lacquer of this invention is catalytically dried, the catalyst beinga strong acid such as p-toluenesulfonic acid. The drying of the castor oil based lacquer is believed to occur via a cationic polymerization mechanism whereby a proton from the strong acid catalyst initiates polymerization through the double bonds of the castor oil. The castor oil may, if desired, be blown, i.e., oxidized, castor oil. The acid catalyzed polymerization, or drying, is initiated at elevated temperatures. While the castor oil based lacquer may be comprised essentially entirely of castor oil, it is preferred that thet lacquer contain other ingredients. The usual castor oil based lacquer is comprised of castor oil, a film forming resin, a solvent, and a strong acid catalyst. If desired, a small amount of a plasticizer may also be present. Generally, the castor oil based lacquer will comprise about 10-65 weight percent, and preferably about 15-60 weight percent, of castor oil; about 10-65 weight percent, and preferably about 15-60 weight percent, of a film resin; about 5-40 weight percent, and preferably about 10-35 weight percent, of solvent; and about 0.5-10 weight percent, and preferably about 1-5 weight percent, of strong acid catalyst. If a plasticizer is present, the lacquer will contain about 0.1-2, and preferably about 0.3-1.5, weight percent of plasticizer.

Examples of suitable film forming resins are alkyd res ins such as those derived from tall oil fatty acids, wood rosin, melamine resins, urea-formaldehyde resins, and mixtures thereof. Suitable solvents may be selected from among aliphatic alcohols and aromatic hydrocarbons. Examples of useful solvents are methanol, ethanol, isopropanol, butanol, benzene, toluene, and mixtures thereof. Examples of strong acid catalysts are sulfuric acid, and preferably, p-toluenesulfonic acid. The plasticizer may be, for example, a polyester wax, dioctyl phthalate, diisooctyl phthalate, octylene glycol, and mixtures thereof.

The convertible castor oil based lacquer may be either clear or colored. When a colorant is present, in the amount will vary depending on such factors as tinting strength and covering power of the colorant as well as the intensity of color desired. While colored castor oil based lacquers broadly comprise a major amount of the lacquer vehicle and a minor amount of colorant, generally a colored castor oil based lacquer will comprise a major proportion of lacquer vehicle and about 2 to 40 weight percent, and preferably about 4 to 20 weight percent, of colorant. By vehicle is meant the clear lacquer without the colorant. The choice of colorant is not critical, colorants in general being useful in the practice of this invention. The colorant may therefore be either a dye or a pigment, organic or inorganic. Examples ofsuitable pigrnents are carbon black, phthalocyanine blue, benzidine yellow, phloxine red, titanium dioxide, colloidal silica,

cadmium red, and cadmium yellow. A suitable dye is Irgacete Red 2 BL.

The ethyl cellulose based coating over which the convertible castor oil based lacquer is applied is derived from an ethyl cellulose based ink or lacquer. The makeup of the ethyl cellulose based ink or lacquer, and hence the ethyl cellulose based coating derived therefrom, is not critical. Like the castor oil based lacquer, the ethyl cellulose based lacquer, and the coating derived therefrom, may be either clear or colored. The ethyl cellulose based lacquer generally comprises a solution of an ethyl cellulose in a suitable solvent. Any of the various types of ethyl cellulose may be used, e.g., N-type ethyl cellulose, T-type ethyl cellulose, and ethyl hydroxyethyl cellulose wherein the substituted cellulose contains both ethyl and hydroxyethyl groups. The lacquer may in addition contain a film forming resin and a plasticizer. Broadly, the ethyl cellulose based lacquer comprises about 7095, and preferably about 80-95 weight percent of solvent and about -30, and preferably about 5-20, weight percent of an ethyl cellulose. If a film forming resin and a plasticizer are present in the ethyl cellulose based lacquer, the lacquer will typically contain about 1-3 weight percent of film forming resin and about 1-4 weight percent of plasticizer.

Examples of suitable solvents for the ethyl cellulose based lacquer are benzene, toluene, methanol, ethanol, isopropanol, methylene chloride, and mixtures thereof. Suitable film forming resins and plasticizers are those exemplified above as suitable for use in the castor oil based lacquer.

As set forth above, the ethyl cellulose based lacquer and the coating derived from the lacquer may be either clear or colored. As with the castor oil based lacquer, when a colorant is present the amount will vary depending on such factors as tinting strength and covering power of the colorant as well as the intensity of color desired. Colored ethyl cellulose based lacquer broadly comprise a major amount of the lacquer vehicle and a minor amount of colorant. The vehicle is the clear lacquer without colorant. Generally, however, a colored ethyl cellulose based lacquer will comprise a major proportion of lacquer vehicle and about 2 to 40 weight percent, and preferably about 4 to 20 weight percent, of colorant. The choice of colorant is not critical, colorants in general, be they dyes or pigments, organic or inorganic, being useful in the practice of this invention. Examples of suitable pigments are carbon black, phthalocyanine blue, benzidine yellow, phloxine red, titanium dioxide, colloidal silica, cadmium red, and cadmium yellow. A suitable dye is Irgacete Red 2 BL. The orange peel effect obtained by the practice of this invention is achieved only when the convertible castor oil based lacquer is applied over an ethyl cellulose based coating and, of course, heated to cause the castor oil based lacquer to dry. When a convertible castor oil based lacquer is applied over a coating based on another material, e.g., nitrocellulose, chlorinated polypropylene, or chlorinated rubber, the resultant coating is smooth and glossy. Thus, there are readily apparent two ways for obtaining a contrast finish where part of the printed or lacquered surface is smooth and part has the orange peel texture. In one method, the entire base coating may be an ethyl cellulose coating and the desired contrast may be obtained by applying the convertible castor oil based lacquer in the desired design on top of the ethyl cellulose based coating. Alternatively, the portion of the surface to be textured may have an ethyl cellulose based coating applied thereto while the remainder of the surface has a coating based on, for example, nitrocellulose or chlorinated rubber. The en tire surface may then be coated with a convertible castor oil based lacquer and heated to thereby produce the contrast finish in the desired design. Of course, the entire surface to be printed or lacquered may be initially coated with an ethyl cellulose based coating and the entire surface overcoated with a convertible castor oil based lac- .quer followedby heating to givea .coated. surface that is completely textured. Further variations in texture and design may be achieved by using dyes and pigments of different colors in the castor oil based lacquer and in the ethyl cellulose based coatingaswell as by having no dye or pigment present in either one or both of the ethyl cellulose based coating or the convertible castor oil based lacquer.

Regarding the temperature required to dry the castor oil based lacquer, it will be understood by those skilled in the art that the higher the temperature,'the shorter the drying time. It will also be apparent that the upper limit to the drying temperature will be determined by the temperature at which the coating and/or substrate begin to undergo thermal decomposition. Generally, however, drying temperatures within the range of about 200 F. to about 450 F., and preferably about 300 F. to about 375 F., are employed.

The following specific examples will serve to further illustrate this invention.

EXAMPLE I Convertible castor oil based lacquers A and B, having the following compositions are prepared. All quantities are parts by weight.

Parts:

Castor oil 11.250 8. 4375 16. 875 19. 6875 9. 375 9. 3750 5. 000 5. 0000 7. 000 7. 0000 Isopropanol 2. 500 1. 3000 p-Toluenesultonic acid 2. 500 0. 7000 When lacquers A and B are applied over ethyl cellulose based ink coatings on paper web substrates and the webs heated at 350 F., a textured, orange peel effect is achieved in each case.

EXAMPLE II A convertible castor oil based lacquer C, having the following composition, is prepared. All quantities are in parts by weight.

C, parts Castor Oil 28.125 Melamine Resin 9.375

Ethanol 5.000 Toluene 7.000

Isopropanol 1.000 p-Toluenesulfonic Acid 1.000

Ethyl cellulose based lacquers D, E, and F, having the following compositions, are prepared. All quantities are parts by weight.

substrates andallowed to dry by evaporation of the solvents. Castor oil based lacquer C is applied over the ethyl cellulose coatings derived from lacquers D, E, and F and the webs are heated at 350 F. In each case, a textured, orange peel effect is achieved in the resultant coatings.

EXAMPLE III A colored castor oil based'lacquer G, containing a dye,

is prepared according to the following recipe. All quantities are in parts by weight.

G parts Castor Oil 51.25 Irgacete Red 2 BL Dye 5.00 Methanol 15.75

Ethanol 6.00 5 Toluene 10.00

Isopropanol 2.00 Melamine Resin 17.00 p-Toluenesulfonic Acid 2.00

When lacquer G is applied over the ethyl cellulose coating derived from lacquer F and the web containing the coating heated at 350 F., a colored textured coating results.

EXAMPLE IV 1" Convertrble castor oil based lacquers H and I, having 0 the following compositions, are prepared. All quantities are in parts by weight.

Parts:

Castor oil 42.000 28. 000 Tall oil alkyd resin.- 0 Melamine resin 00 Urea formaldehyde res Polyethylene Ethanol Isopropanol 2.800 1 000 Toluene 16. 500 3 000 p-Toluenesulfonic ac 2. 500 1 000 Dioctyl phthalate- 1. 125 Polyester wax 0. 125 Octylene glycol 0. 375 Pi ment 6. 500

Ethyl cellulose based lacquer I, having the following composition, is prepared. Quantities are in parts by weight.

. I, parts Toluene 94.0 Low viscosity ethyl hydroxyethyl cellulose 6.0

Lacquer I is applied to web substrates and allowed to dry by evaporation of the toluene solvent. Castor oil based lacquers H and J are applied over the ethyl cellulose coatings derived from lacquer I and the webs containing the coatings heated at 350 F. In each case, a textured coating is obtained, the textured coating being colored in the case Where pigmented lacquer J is used.

EXAMPLE v A castor oil based lacquer K and an ethyl cellulose based lacquer L are prepared according to the following recipes. All quantities are in parts by Weight.

Ethyl cellulose based lacquer L is applied to a web substrate and allowed to dry by evaporation of solvent. Lac quer K is applied over the ethyl cellulose coating derived from lacquer L and the web containing the coating heated at 350 F. A textured black coating is obtained.

While this invention has been illustrated by the presentation of specific embodiments thereof, it will be understood that the scope of the invention is limited only by the appended claims.

What is claimed is:

1. A process for producing textured coatings comprismg:

a. applying a castor oil based lacquer over an ethyl cellulose coating on a substrate, said lacquer comprising about 10 to 65 weight percent of castor oil, about 10 to 65 percent of a film forming resin, about 5 to 40 weight percent of a solvent, and about 0.5 to 10 weight percent of a strong acid catalyst; and

b. heating to cause said castor oil based lacquer to dry.

2. The process of Claim 1 wherein the castor oil based lacquer is applied to only a portion of the ethyl cellulose coating.

3. The process of Claim 1 wherein said castor oil based lacquer comprises about 15 to 60 weight percent of castor oil, about 15 to 60 Weight percent of a film forming resin, about 10 to 35 weight percent of a solvent, and about 1 to 5 weight percent of a strong acid catalyst.

4. The process of Claim 3 wherein said strong acid catalyst is p-toluenesulfonic acid.

5. The process of Claim 3 wherein said castor oil based lacquer contains in addition about 0.3 to 1.5 weight percent of a plasticizer.

6. The process of Claim 4 wherein said castor oil based lacquer contains about 4 to 20 weight percent, based on the total lacquer composition, of a pigment.

7. The process of Claim 4 wherein said ethyl cellulose coating is derived from an ethyl cellulose based lacquer comprising about to weight percent of a solvent and about 5 to 20 weight percent of an ethyl cellulose.

8. The process of Claim 7 wherein the ethyl cellulose is selected from the group consisting of ethyl cellulose and ethyl hydroxyethyl cellulose.

9. The process of Claim 8 wherein said ethyl cellulose based lacquer contains in addition about 1 to 3 weight percent of a film forming resin and about 1 to 4 weight percent of a plasticizer.

10. The process of Claim 8 wherein said ethyl cellulose based lacquer contains about 4 to 20 Weight percent, based on the total lacquer composition, of a pigment.

11. The process of Claim 8 wherein said heating step is carried out at about 300 to 375 F.

References Cited UNITED STATES PATENTS 2,456,670 12/1948 Beynon 117-41 3,565,720 2/1971 Nimocks 117-41 WILLIAM D. MARTIN, Primary Examiner I. A. BELL, Assistant Examiner U.S. Cl. X.R. 1178, 41, 73, 76, 87, 90, 155, 157 

